The present invention broadly relates to a bale-opener machine and, more specifically, pertains to a new and improved construction of adjustable grid for the extraction arm of a bale-opener machine for adjusting the depth of penetration or projection of drivable fiber flock extraction elements extending between the grid bars which are substantially transversely arranged relative to the longitudinal direction or direction of extent of the extraction arm.
An adjustable grid of this type is known, for example, from European Published Patent Application No. 86103135, published Oct. 20, 1986 under Publication No. 0,199,041, and U.S. Pat. No. 3,381,341, granted May 7, 1968.
It is hitherto customary to open bales, for instance fiber bales, by means of a bale-opener machine, the bales being arranged in a row one behind the other and substantially parallel to the direction of motion of the bale-opener machine. It is known by experience that some bales are harder or softer than the average bale and that even the bale compression varies as a function of the extent to which the bale is opened. Due to such differences in bale compression, it is necessary to vary the depth of penetration or projection of the fiber flock extraction elements of the bale-opener machine. The depth of penetration or projection of the fiber flock extraction elements is defined as the distance by which the fiber flock extraction elements project underneath or below the grid which slides over the surface of the bales. The depth of penetration differs from the feed depth which is a dimension for the vertical or elevational adjustment of the entire extraction arm of the bale-opener machine when the latter again moves along the row or bales.
The hitherto proposed mechanisms for setting the depth of penetration or projection of the fiber flock extraction elements by adjusting the grid are relatively complicated. For example, in the aforementioned U.S. Pat. No 3,381,341, the therein disclosed textile finer bale-opener unit requires a number of bevel gears to adjust the grid and such gears alone represent a relatively high constructional expenditure. In order to adjust the grid at both ends, either an additional complicated gear system or two separate drive motors for the corresponding gear wheels arranged at both ends of the grid are required, in which latter case it would then be necessary to provide a synchronization of the two motors. In the known or prior art arrangement it is also not possible to adjust the inclination of the grid.
The apparatus for extracting fiber flocks or tufts from textile fiber bales disclosed in the aforesaid European Published Patent Application No. 86103135 (publication No. 0,199,041) enables the depth of penetration or projection as well as the inclination of the grid to be adjusted, but also requires four drive motors which have to be synchronized at least in pairs.